I tried everything 2 or 3 times over...new needles, re-threading top & bottom thread, playing with the tension dial, using knotted thread & a dollar bill to clean the tension disc, completely took out the bobbin & case to clean out, and clean the whole machine (wasn't very linty at all), but I am now pretty sure that it was the cheap thread that I was using.
Originally Posted by willquilt81
try a new needle...sometimes that helps with my longarm when it gets loopy on the back...